Study of the Effect of Mining with Transition from Open-Pit to Underground and without Protective Coal Pillar on Slope Stability

2014 ◽  
Vol 1010-1012 ◽  
pp. 1475-1481
Author(s):  
Shi Guo Sun ◽  
Yanan Yi ◽  
Lu Jin ◽  
Jia Huan Shi

As this mining area has a shallow coal seam and a dump, therefore, the mining for the deep resources uses the method of transition from open-pit to underground without protective coal column. In this paper, the numerical simulation method is used to analysis the surface subsidence and slope stability from the two different mining schemes which are from inside to outside, and from outside to inside, in order to obtain the optimization of mining scheme. And settlement and slope stability of rock body are further analyzed from two aspects of fully exploit from the tendency and from toward, the result of an overall slip slope failure caused by underground mining is found. So that in the process of exploitation, corresponding prevention and control measures to the slope safety has been put forward, ensuring smooth production.

2021 ◽  
Author(s):  
Bowen Liu ◽  
Zhenwei Wang ◽  
Xinpin Ding ◽  
Zhitao Wang ◽  
Bin Li

Abstract Under a background of coordinated open-pit and underground mining engineering practice in the Pingshuo mining area, a combination of numerical simulations and similar-model experiments was used to study the influence of the underground mining direction on slope deformation in two dimensions. The results show that the disturbance caused by inverse-slope mining is more obvious than that caused by along-slope mining. Underground mining presents an asymmetric influence on the open-pit slope; the slope rock mass on the open-off cut side is disturbed more than that on the coal-wall side. Compared with the slope in front of the advancing direction of the underground mining face, the degree of rock-mass damage and stress concentration of the slope of the open-off cut side are more serious. As such, in coordinated open-pit and underground mining practice, an along-slope mining direction is recommended to reduce adverse effects on slope stability and improve the recovery rate of coal resources.


2013 ◽  
Vol 634-638 ◽  
pp. 3277-3281 ◽  
Author(s):  
Shi Guo Sun ◽  
Hong Yang ◽  
Chun Sheng Li ◽  
Bao Lin Zhang ◽  
Jia Wang ◽  
...  

The stability state of slope rock mass is relating to each other’s relative location during the transformation from open-pit to underground mining, it’s the most disadvantageous influence on the slope stability when the underground mining area is located in the toe of slope, and it’s the best influence as in the slope extracellular region. Slope stability factor changes with the geometric dimensions of underground mining increased, but not in direct proportion. Under the condition of constant geometric dimensions of mining area, the influence on slope stability is changing with the mining depth increased. Thus indicating that the influence on slope stability by underground mining has its spatial property, and to determine the specific influence value requires a combination of many factors, such as the relationship of relative spatial position, the geometric dimensions of mining area, engineering geological conditions and so on.


2012 ◽  
Vol 472-475 ◽  
pp. 3171-3177 ◽  
Author(s):  
Shi Guo Sun ◽  
Pei Xin Dong

At present, technology for open pit combined underground mining is one problem about mine. It mainly involves some problems, such as how to design deep resources exploitation, how to evaluation slope stability and so on. Combining the underground mining effect with their characteristics and function attributes influenced by the slope deformation, this paper considers the both composite superimposed law, and derives the calculation method of the slope stability under comprehensive function. Accordingly, explore the influence law of slope stability, induced by underground mining area and the relative position and the space and geometry size changes of slope body. And the final purpose is to provide the scientific basis for design and safety assessment of deep resource extraction.


2014 ◽  
Vol 989-994 ◽  
pp. 3070-3074
Author(s):  
Qing Wen Li ◽  
Lan Qiao ◽  
Lu Chen

Further excavation is extraordinary significant to the sustainable development of mine. For the rock slope, three-dimensional geostress in the deep mining area are presented complex and high, which were caused by previous excavation. Also, it is important to obtain the accurate geostress in mining area, which is the necessary precondition for determining the remaining ore mining scheme and the slope stability. In this paper, based on the in-situ geostress monitoring date, a 3D numerical model alongside the physical dimensions was built in finite element software FLAC3D, to accept the constitutive parameter and monitoring data, to predict the 3D stress and displacement distributions and detail failure information, to estimate stability of mining area.


2021 ◽  
Vol 882 (1) ◽  
pp. 012059
Author(s):  
Bagaraja Sirait ◽  
Zulfahmi

Abstract Open-pit mine is a mining method by excavating overburden strata to get coal seam near the surface. One of potential hazard often occur in mining area is slope failure. The hazard can be prevented by performing geotechnical study. The study is required to provide recommendations regarding safe design of slope geometries in both open-pit and disposal sites. This paper produce information related to the results of slope stability analysis especially on the disposal embankment. The analysis is performed by using the limit equilibrium method. It is also produce the bearing capacity analysis of subsurface strata in disposal site. The analysis is carried out to determine the ability of the strata to burden the load of disposal embankment above. The location was selected in a site of open-pit coal mine in Indonesia. The results will become consideration for management in designing slope disposal and choosing the location of disposal facilities.


2011 ◽  
Vol 383-390 ◽  
pp. 2201-2205
Author(s):  
Xin Xi Liu ◽  
Xue Zhi Wang

Analysis on the characters of ground subsidence of Yangjiaping mining area, with same excavation depth and recovery coefficient, the numerical simulations to nonlinear large deformation using finite-difference method(FLAC) are achieved on the different strip extraction schemes that adopted different mining and reservation width. The result indicates that the subsidence values and horizontal deformation increases with the increasing of the strip extraction width on condition of the same recovery rate. Based on probability density function (PDF) method, the relationship of the coal pillar width, the mining width and ground deformation is acquired, which is some useful reference for using the strip extraction method to control the surface movement and deformation.


2018 ◽  
Author(s):  
Zhang Jin

Geohazards in mining areas are mainly ground subsidence, slope landslides and ground cracks, surface cover degradation and environmental ecological pattern destruction. The classification and rank of terrain slope and the feature area extraction of the slope are the important content for the correlation analysis with the geohazards. The slope classification and rank index system for soil and water conservation, land use and man-made ground disasters was analyzed. According to the characteristics of open pit and underground associated mining area, we comprehensively analyzed the spatial correlation between different ground disaster and terrain features and landform types, and propose a new slope ranking index, dividing slope zones and forming slope classification map. Especially slope area of 35-45 degrees and more than 45 degrees was extracted, and the relationship between regional geohazards and slope zone was analyzed. The application of terrestrial laser scanning technology to establish open-pit high precision digital elevation model, extraction of slope, slope type, gully density characteristic factor, topography factor data sets are established, and correlation analysis, to enhance disaster information content.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.


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